解题方法
1 . 已知数列
的前n项和为
,且
,
.
(1)求数列
的通项公式;
(2)在
与
之间插入n个数,使这
个数组成一个公差为
的等差数列,在数列
中是否存在3项
,
,
(其中
成等差数列)成等比数列?若存在,求出这样的3项,若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/beb08c935c5a6dae2b2e53cfa8eac740.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090426eb29836bc30c006b3739c08057.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3468a665ac713ab7b400c672f19650a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82e260b088f071983f254ce8f5163fcd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b783cf91e34e692ce8e171f0965cb53f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8598379ec01edc16c72c1d3fa3ce81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8904e7018ec79c8b0efdcb3ba67cb7cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2554efe1860dc6c769c34d8cfa6de3e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7955013519718c9ac993531062495e95.png)
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2 . 设数列
的前n项和为
,
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9ba984e922424ae65819c8a2bc27c64.png)
A.![]() |
B.当且仅当![]() ![]() |
C.![]() |
D.![]() ![]() ![]() ![]() ![]() ![]() ![]() |
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3 . 数学中也有一朵美丽的雪花——“科赫雪花”.它的绘制规则是:任意画一个正三角形
,并把每一条边三等分,以三等分后的每边的中间一段为边向外作正三角形,并把这“中间一段”擦掉,形成雪花曲线
.重复上述两步,画出更小的三角形,一直重复,直到无穷,形成雪花曲线
.设雪花曲线
边长构成数列
,面积构成数列
.若
的边长为3,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.png)
________ ;
=________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2708fa6298e52f617383efc175b71ddc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b9cb8e6ff801523b0304576cd69fd2d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd22d0343656ab15fc226ccf9f154825.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d013861990cf331c82eb453416ae31bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2708fa6298e52f617383efc175b71ddc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/27/8690a193-bd83-4259-a647-ecdc5fa7bed9.png?resizew=322)
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4 . 设各项均为正数的数列
的前
项和为
,且
.
(1)求数列
的通项公式;
(2)若数列
满足
,设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88f1e9969e77114d09887876937d5eef.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb5a32c6efb88e201c663c471e9e6d09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7cf883202b8ef8c25fa641f128b70a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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名校
解题方法
5 . 已知数列
的前
项和
,且
恰好有一项是负项,则
的值是_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d1905efcccf109907d8e91c1f55911c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9f2eb65f2fe6546a5e318343d25fe66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fee1a56a69794fb06570b81790a23dc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d1905efcccf109907d8e91c1f55911c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4e12c93e841b2afb8b07399eb3d1f5f.png)
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2024-02-23更新
|
589次组卷
|
2卷引用:湖北省武汉市华中师大第一附中2023-2024学年高二下学期数学独立作业(一)
6 . 已知数列
的前n项和为
.
(1)求证:数列
是等差数列;
(2)设
的前n项和为
;
①求
;
②若对任意的正整数n,不等式
恒成立,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/404378873d8f90e59cac43dbe6bb1562.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4689920e36d2ac304503d852083b07a4.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fb5d73cea14ac60937f8d5a4f5f0c1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
②若对任意的正整数n,不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6abf942265247031ce354221f22ac6ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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2024-02-23更新
|
548次组卷
|
2卷引用:湖北省沙市中学2023-2024学年高二上学期1月期末考试数学试题
名校
7 . 已知等差数列
与
的前
项和分别为
,
,且
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf0665d6fd8ea6f4592ca889af698851.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d6538fcc8e63a23a36e72dacc5b65c.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2024-02-23更新
|
1910次组卷
|
4卷引用:湖北省新高考联考协作体2023-2024学年高二下学期2月收心考试数学试题
解题方法
8 . 已知数列
的前
项和为
,且
,设
,若数列
是递增数列,则
的取值范围是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39e08e69e19c3b52b52913daf7363ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ad6a3355330364acccc23e28ee07166.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
9 . 设数列
的前
项和为
是公差为1的等差数列,数列
为等比数列,
.
(1)求
,
的通项公式;
(2)求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/606fa3f4bdf082e4fede26c60d35f59d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ac68d71ee62a9f8e07376d857224121.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ea2059d41da264b08aa7692f82fc1fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/939366f52d33ae3f69b101251eaa02da.png)
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2024-02-20更新
|
521次组卷
|
2卷引用:湖北省荆州市八县市区2023-2024学年高二上学期1月期末联合考试数学试题
解题方法
10 . 已知数列
的前
项和
,数列
满足
.
(1)求数列
的通项公式;
(2)由
构成的
阶数阵如图所示,求该数阵中所有项的和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a3bc907fe03ad648a78548de36bcc6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e764296a62a7def78e39370f746b4663.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0197eeeeaafec6b1fdd7bb8509572f6b.png)
(2)由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a55e03428497ac0ea2aa80fe5bdcd939.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/767f5a4746f04db68386fac3970b1ed1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/17/468426cc-7bf3-4194-bec0-6394485723d6.png?resizew=158)
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